Unified Routing Requirements for IPng (RFC1668)
Original Publication Date: 1994-Aug-01
Included in the Prior Art Database: 2019-Feb-12
Internet Society Requests For Comment (RFCs)
D. Estrin: AUTHOR [+2]
The document provides requirements on the IPng from the perspective of the Unified Routing Architecture, as described in RFC 1322. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.
Network Working Group D. Estrin Request for Comments: 1668 USC Category: Informational T. Li Cisco Systems Y. Rekhter T.J. Watson Research Center, IBM Corp. August 1994
Unified Routing Requirements for IPng
Status of this Memo
This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
This document was submitted to the IETF IPng area in response to RFC 1550. Publication of this document does not imply acceptance by the IPng area of any ideas expressed within. Comments should be submitted to the firstname.lastname@example.org mailing list.
1. IPng Requirements
The following list provides requirements on the IPng from the perspective of the Unified Routing Architecture, as describe in RFC 1322.
1. To provide scalable routing, IPng addressing must provide support for topologically significant address assignment.
2. Since it is hard to predict how routing information will be aggregated, the IPng addressing structure should impose as few preconditions as possible on the number of levels in the hierarchy. Specifically, the number of levels must be allowed to be different at different parts in the hierarchy. Further, the levels must not be statically tied to particular parts (fields) in the addressing information.
3. Hop-by-hop forwarding algorithm requires IPng to carry enough information in the Network Layer header to unambiguously determine a particular next hop. Unless mechanisms to compute context-sensitive forwarding tables and provide consistent forwarding are defined, the requirement assumes the presence of full hierarchical addresses. Therefore, IPng packet format must provide efficient determination of the full hierarchical
Estrin, Li & Rekhter [Page 1]
RFC 1668 Unified Routing Requirements for IPng August 1994
4. Hierarchical address assignment should not imply strictly hierarchical routing. Therefore, IPng should carry enough information to provide forwarding along both hierarchical and non-hierarchical routes.
5. The IPng packet header should accommodate a "routing label" or "route ID". This label will be used to identify a particular FIB to be used for packet forwarding by each router.
Two types of routing labels should be supported: "strong" and "weak".
When a packet carries a "strong" routing label and a router does not have a FIB with this label, the packet is discarded (and an error message is sent back to the source).
When a packet carries a "weak" routing label and a router does not have a FIB with this label, the packet...